This study investigates why and when employees’ observations of supervisors’ ostracism of coworkers elicit their own feelings of guilt. In this connection, observers’ silence might function as a mediator, and leader–member exchange quality could moderate the process. The tests of these predictions rely on two studies, undertaken in Pakistan: a temporally separated field study using three-wave data (N = 219) and a scenario-based experiment (N = 118). The combined results indicate that employees feel guilty for remaining silent when they witness (...) supervisor ostracism of other colleagues. The positive relationship between such observations of supervisor ostracism and silence behavior is more pronounced among employees who enjoy high-quality relationships with their supervisor. In addition to establishing key theoretical insights, this article alerts organizations to a critical mechanism (silence to avoid upsetting supervisors) by which employees’ observations of how supervisors ostracize others can escalate into their own sense of guilt. (shrink)